This invention relates to an aperture control mechanism in an interchangeable lens single lens reflex camera.
In a conventional interchangeable lens single lens reflex camera, the aperture drive member on the camera side is engaged with an aperture release member on the interchangeable lens side to automatically stop down the lens. In a camera having a so-called "EE function" wherein the aperture diameter of the interchangeable lens is set by data from the camera side, the position of the aperture release member on the lens side, which release member is urged by a spring or the like, is controlled by suitably changing the position of the aperture drive member on the camera side according to data provided during the stop down operation, to thereby control the aperture diameter.
In such a control system, the relationship between the position of the aperture drive member and the aperture diameter is, in general, fixed. Therefore, when the interchangeable lens is mounted on the camera and a positional mounting error occurs, the aperture diameter may not be correctly controlled because the aperture release member and the aperture drive member may not both be in their proper relative positions. This problem may also arise due to manufacturing errors or the wear of the aperture release plate and the aperture drive member.